The invention relates to a test device for optical waveguides using an optical receiver which exhibits a coupling device as well as a light-sensitive element disposed in the radiation field of an emission signal to be coupled out and with which an evaluating device is associated.
A test device of this type is disclosed in DE-C2-34 29 947. It permits the assessment of a splice position of an individual optical waveguide. An emission signal is injected by means of a coupling device into the optical waveguide ahead of the splice position and is coupled out, after the splice position, on the reception side by means of a second coupling device. The exit field of the coupled-out emission signal is received by a photodiode and subsequently displayed.
If a plurality of optical waveguides were inserted into this known test device, then it would be possible to measure only the common, superposed sum of the individual radiation fields of the optical waveguides. It would not be possible to draw from this superposition sum conclusions as to the selective, characteristic individual radiation fields of the inserted optical waveguides, since a functional dependence between the selective test variables and the superposed sum cannot be derived. An individual statement, for example, as to the splice attenuation of a specific optical waveguide within a test device according to the prior art is not possible.
DE-A1-39 11 429 discloses a device for aligning two fiber ends of optical waveguides in a splice position. Shadow images of the two optical waveguide ends are generated by an illumination of the two fiber ends of a single optical waveguide from outside. These two shadow images are received by at least two stationary, separate photosensitive surfaces, which are disposed along the longitudinal axis of the optical waveguide. A control variable for a positioning device for the in-line alignment of the fiber ends is derived from the separate electrical test signals generated by the photosensitive surfaces, by comparison. Statements concerning characteristic quantities describing the transmission behavior of the optical waveguide are not possible with such a device. In particular, no splice attenuation testing can be carried out in this manner.